Ralte scored from the spot as the match looked to headed for extra time to dash Aizawl's hopes and help Khalid Jamil's side into the last-four stage.
The game that was balanced at both ends went to the Red & Golds favour in the final minute of the injury time in the second half when Aizawl FC goalkeeper in order to stop a marching Kromah conceded a penalty that was duly converted by Ralte.
The first half began on a slow note, however Kingfisher East Bengal FC soon caught up and started attacking in quick succession through Syrian Mahmoud Al Amna and Nigerian Dudu Omegbemi.
But the Mizoram outfit showcased their class by denying East Bengal FC to even score once.
Aizawl FC did put up an attack with a few shots on the goal as well but couldn't find success in their attempts.
It was the Bengal outfit however who came really close to scoring on a couple of occasions but some brave goal-keeping from Aizawl FC goalkeeper Lalawmpuia ensured that the first 45 minutes of the game ended evenly balanced without any goals being scored.
The second half began with East Bengal pressing hard to score but Aizawl FC goalkeeper Lalawmpuia was too tough for the Red & Golds to pass through.
It was Lalawmpuia's heroics at the goal post that kept Aizawl FC alive in the game till the last minute before the youngster made the only mistake of the game conceding a penalty in the last minute of the injury time.
Aizawl had missed their closest chance to score a few seconds back through Andrei Ionescu.
East Bengal's Ralte made no mistake in converting the penalty to his favour, and sealing their semi-final spot at the Hero Super Cup 2018.
The second quarterfinal will be played between I-League outfits Mohun Bagan and Shillong Lajong April 11.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
